| Anotation: | Hydromagnetic processes taking place in Earth’s liquid core act as a source of geomagnetic secular variations. The key region, where the field is advected by large-scale flows and modified otherwise is the one beneath the surface of the core. Core dynamics is manifested by changes of intensity and position of the magnetic field’s characteristics measured on the Earth’s surface. One of its signs is westward drift of the non-dipole part of the geomagnetic field which directly shows advection of the field by flows in the core. Reversed flux patches identified at the core-mantle boundary are part of it. On the Earth’s surface they appear as anomalous regions of low intensity. Analytic kinematic study of verical geomagnetic variation [10] explains them as a consequence of cooperation of 3-dimensional convection in the diffusionless main volume and resistive effects in the hydromagnetic boundary layer at the mantle. Numerical solution of the problem may help to better understand the complex dynamics of the core. [10] Marsenić, A., A kinematic model of vertical geomagnetic field variation resulting from a steady convective flow. Geophys. Astrophys. Fluid Dynamics, DOI: 10.1080/03091929.2013.840723.
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